Thrushes (Turdidae)
ORDER
The order PASSERIFORMES (pronounced pas-ser-i-FOR-meez) encompasses one hundred and eighteen families of birds, among which are included the waxwings, swallows, and thrushes.
FAMILY TAXONOMY
One hundred eighty-three species of thrushes in twenty-four genera make up the Turdidae (pronunciation TUR-duh-dee); a family that occurs on many islands and all continents except for Antarctica.
NORTH AMERICA
Thrushes are well represented in North America with sixty species in thirteen genera (including the extinct Grand Cayman Thrush and Amahui of Hawaii). This family includes well known birds such as the American Robin and bluebirds, and lesser known birds such as the Townsend's Solitaire of western mountain forests.
KNOWN FOR
Thrushes are most well known for their beautiful flute-like songs; an attribute shared by many North American thrush species. The caroling song of the American Robin is often viewed as a harbinger of spring.
PHYSICAL
Small birds with plump bodies, most thrushes have medium-length tails, slender, medium-length bills, and strong legs that work well when foraging on the ground for invertebrates. Their fairly long wings are adaptations for migratory behavior, and in the case of the solitaires and bluebirds aid with their foraging strategies.
COLORATION
Thrushes come in a variety of colors from the beautiful blues of the bluebirds and Bluethroat to the reddish-orange underparts of the American Robin, orange and gray of the Varied Thrush, and the earthy tones of other forest species. All juvenile thrushes are spotted on the underparts, a characteristic also shown by the adults of the Wood Thrush and a few other species.
GEOGRAPHIC HABITAT
In North America, aside from the American Robin and bluebirds, most thrushes are birds of woodland and forest. The Wood Thrush shares the eastern deciduous forests with the Veery while out west, the ethereal tones of the Varied Thrush vie with the songs of Hermit and Swainson's Thrushes in the tall coastal rainforests. The Gray-cheeked Thrush breeds further north in the boreal zone and the Townsend's Solitaire sings from the mountain conifers.
MIGRATION
Thrushes are excellent fliers and make use of this trait for short and long-distance migrations with species such as the Veery and Swainson's Thrush wintering well south of the equator.
HABITS
Aside from open country species like the American Robin and bluebirds, thrushes tend to be shy, inconspicuous birds that quietly forage for invertebrates on the forest floor. Although robins use this foraging strategy, bluebirds snatch insects by flying to the ground and solitaires sally into the air to catch insects. Solitaries also feed on fruit; a trait many thrush species share, more so outside of the breeding season when they also tend to form loose flocks.
CONSERVATION
None of the thrushes of mainland North America are considered threatened although populations of the Wood Thrush have declined in many areas possibly due to deforestation on its breeding and Central American wintering grounds. Most Hawaiian Solitaries, though, have become critically endangered or have gone extinct because of changes to their fragile habitat and susceptibility to avian malaria. Ornithologists are also concerned about the future of some species, such as the Bicknell's Thrush, due to destruction and development of their small wintering habitat areas.
INTERESTING FACTS
Eastern Bluebirds populations have declined as a result of being out competed for nesting sites by more aggressive European Starlings. Fortunately, putting up nest boxes for the cavity nesting bluebirds has helped this species in many areas.